The Hørning Perikles Speaker came first to my attention last September, at the HiFi Show in London. But I hear you asking: "Who the f**k is Perikles?" Well, something in the back of mind wanted to remind me of, but even I cannot remember any stuff I learned in the last Millennium, so I looked it up at the Encyclopedia Britannica on-line…. Perikles was an Athenian Statesman who was instrumental in the building of Athenian Democracy, around two and a halve millennia ago. Perikles was a bit of populist basically, also said to be of great virtue and integrity. He gave (some) power to the people, something previously unattainable for them.
And well chosen the name is too, for the modern Perikles Speakers aim to offer integrity and virtue (in a musical sense) and to bring the previously unattainable to the People, in this case a rather special Sound. I have been aware of Hørning Speakers for a good while, but all that I have seen before where huge, hulky, bulky and expensive Monsters…. Not populist at all. So, what is it that is different about the Perikles? Well, I took immediate interest because of the use of Lowther Drivers and a decent level of Sensitivity that should work well with modest powered Valve Amplifiers. The Speakers look like a very high quality floorstanding tower speaker so popular these days.
At less than 12 " wide and about 42 " high, dressed in gorgeous light cherry real wood veneer I immediately liked the way the speaker looked. What is more, I thought that even the proverbial spousal disapproval would not find any ammunition with this speaker. On the Front are two modest looking drivers, the big and bad woofer is mounted in the rear, out of sight. As the speaker is meant to be used near the room corner, this might be one of most spouse friendly speakers around.
Only my girlfriend did not like them much. She said "Our Speakers (since when are the OURS anyway!) are much better. They are much bigger, aren't they? This one is so small!" (she does like things in larger packages).
Anyway, the Perikles is actually a genuine 3-Way Speaker with over 96db/2.83V/m sensitivity, horn-loaded, with a modified Lowther operated as full range, supported by a 12" cast frame Woofer and a special Tweeter. The cost for that potent package? A measly 2,449 Pound in the UK, at today's exchange rate that is about 3,650 US Dollar and that includes the customary 17.5% VAT (Viciously Added Tax) in the UK. True, I have no clue what price a US Importer will set, but I smelled a Bargain. Not your average HiFi Magazine Style "This $ 300,000 Loudspeaker must be counted as the greatest bargain of all times" Bargain. NO A REAL BARGAIN KIND BARGAIN. And believe me, everyone in Britain is bargain hunting all the time. Bargains have replaced the Anglican faith as the most common religion and rank up there next to winning the lottery. We know our bargains here in blighty.
Here we have a Loudspeaker that will work with any modest SE Valve Amplifier, I thought, at that rather attractive price too…. It looks good and even sounds quite good, as far as one can tell such things under show conditions. What to do?
Well, I did what each and every self-respecting Reviewer would do. I begged and groveled and groveled and begged. Shamelessly. Incessantly.
Eventually I managed to wear UK Importer Matthew Jameson (Orpheus Audio of Standish) down and delayed by some "running changes" to the Speaker I finally received my review pair in March this Year. I will keep a thorough explanation of the technology and my measurements for the "Geeks only" section further down, I'll rather tell you about how these Speakers sound.
Maestro, Music Please
When Matthew brought the Perikles over to my Place we hooked them up immediately to my "Svetlana Legacy 300B Amplifier". Replacing my own (DIY and based on antique Drivers of unbelievable quality and build) "Magnificat" Speakers, the Perikles where up against some tough competition. Yet they pulled through. Sure, there where differences in sound and quality, but cold out of the box, not set up specifically well and in a not much optimized system the Perikles showed a lot to commend it. What is especially good is that cohesiveness, that internal integrity of the Music that most good Speakers with wideband and full range Drivers seem to manage. I really liked what I heard and after a few selections of music Matthew took his leave and left me alone with the new toys…
It took me a while of experimenting and changing the placement of the Speakers to get the soundstage up to what I'm normally used to. I ended up with the Perikles toed in at about 45 degree, spaced very wide at around 2.8m with around 3m listening distance, their backs about 0.75m from the rear walls. I also overall found the Perikles to sound ever so slightly too laid back. This led to me replacing the smooth but detailed sounding Svetlana 300B Output Valves in my "Legacy" Amp with 2A3's (it only takes two minutes to readjust). With most speakers I prefer the authority, warmth and dynamics offered by the 300B, finding the 2A3 often to sound slightly thin, threadbare and lacking in Bass Impact. On the Perikles this 2A3 sound seemed to harmonize very well. All the better news for any potential buyer, as all you need to get great sound from this speaker is a good 2A3 Amp. These are not exactly found on all street corners, yet in recent years quite a few nice ones have become available at fairly low cost.
The Perikles have special adjustable ports on the backside, which allow to partially compensate for the differences in distance to the rear wall of the Room. If the Bass grows too heavy, you open them up a bit, close them up for more bass. Neat. I found that with a good deal of distance to rear wall (the Speakers are meant to be quite close to rear walls) the sound was best with the ports almost fully closed. This gives a very crisp and exceptionally well defined Bass, combined with very good pace and rhythm. The Bass does not reach overly low though, a price to pay for the modest size. I found, that fundamental Notes on the upright Bass (or 4-String E-Bass) where reproduced well, fundamental notes of the Piano Grand (that is about 32 Hz) suffered somewhat but where audible. So, the bass covers the musically relevant spectrum reasonably well, really low Pipe Organ Notes are out, however.
What is exceptional about the Perikles Bass is the accuracy of Pitch and the Speed. Many Speakers with plenty of low Bass seem to pull Bass instruments a little of Pitch, making for this often quoted "one note" Bass. Not here though. Listening to some Reggae courtesy of Bob Marley and the Wailers "Exodus" revealed a bass that did it all and remained true to the notes played. Putting on some Rush showed that the Perikles have the ability to resolve the often extremely fast played double kick drums when Neil gives them some real abuse.
Why do I go on about this so much? I have heard quite a few Lowther based Speakers that stood little chance to move enough air for that kind of performance. Neil's Drums had speed, but no body. Reggae Bass lacked all the Fundamentals and was softened out in impact. Now this is not to say that all I ever listen to is Heavy Metal and Reggae, but I do listen to this kind of music and how it fares is important to me. Have you ever heard Lowther's and wished for more crunching, floor shaking, stomach churning Bass while keeping the speed and the ability to delineate Bass Notes Lowther's do so well? Your Prayers must have been heard. Yes, you can get Loudspeakers that will play lower than the Perikles does, but for most music you don't need to.
Okay Bass Head's, this section was for you, but what about "real" Music? On of my recent favorites has been Vivaldi's Gloria in D-Minor (on the Louiseu Lyre Label - an "audiophile" sublabel of Decca dedicated to early music performed on original instruments). This is an exceptional recording also one that is ruthless in revealing weaknesses in the playback system. Combining Strings, Harpsichord, massed Vocals, Soprano soli and Organ it exercises all the "problem" regions of speakers and has incredible dynamics. On really good Systems the presentation is as close to lifelike as it gets. Here the Perikles faired also quite well, failing to start to shout with massed Vocals or the Soprano soli, offering a good harmonic range for harpsichord Notes and even the organ has heft and impact.
Not bad at all, I have heard a number of well respected "audiophile" Speakers really fall to pieces with that recording when played reasonably loud. That said, the Perikles did commit some sins of omission. There seemed a little less detail that I'm familiar with on this record, the soundstage was overall flatter and more laid back than I like. The "laid back" characteristic remarked on before seemed to rob the music of some of the life and vibrancy that is present on this recording.
But hey, I'm comparing the Perikles here with systems like the full-blown Beauhorn Virtuoso Reference System with Visaton Subwoofers and Super Tweeters. Or perhaps top-notch Electrostatic Systems like the Inner Sound Eros and the DIY System my friend Jon keeps around (2.5m Tall Panels, directly driven from 845 Push-Pull Amplifiers with no intervening Transformer. Also such systems like the Wilson Audio Watt/Puppy (MK III please - I don't much care for the later ones) or the Orchid Audio Speakers I recently had around make good comparisons for Speakers that dig out more detail and have a bit more airy a soundscape. We are talking here speakers for at least twice and more than the price of the Perikles and speakers that are much larger and less convenient to place as well. I have heard few Speakers at anywhere near the price of the Perikles that offer such dynamics, such vibrancy and impart so much energy to the Music.
An Area that receives little coverage in the US Press is the classically British P.R.A.T. thing. P.R.A.T. is short for Pace, Rhythm, Acceleration, Timing and denotes the ability of a system (or a specific component) to convey rhythm and tiny inflections in timing. A track I like really much to assess this is the "Unsquare Dance" from my "The best of the Dave Brubeck Quartet" Album (1967 Columbia pressing). This is a piece that is pure rhythm, but not you usual 3/4 or 4/4 Rhythm, instead a very different figure (7/9) that shifts and changes, making toe tapping along a challenge. On many Systems and Speakers that I have subjected to this track it does nothing for me. Boring, uninvolving basically pants. Yet on the right System this things swings. Wow. Do the Perikles make it swing? You betcha. No, again, they don't make track as involving as some of the best I ever heard in that department, but they don't fall very short either. And remember, "It ain't mean a thing, if it ain't got the swing"… Give us the Low-down, darn it… This is simple.
If we view the Perikles in the light of it's price I have heard nothing that can play as loud on very little power. Nothing that offers this almost absolute cohesiveness and integrity of the Music, that allows the Music to readily communicate it's emotional content. You can find Speakers with a little less "laid back" character, with better soundscaping and you can find even much cheaper speakers. There are some that have lower coloration's, not that the coloration's present in the Perikles are that strong. Indeed I cannot put my finger onto any specific item, there just sometimes seems to be a slight tonal "strangeness". There are many Speakers out there that can offer better measurements, a better known "badge" or more street creed.
Non of them however would be Speakers I would want to live with in the long run. They all to my ears fail to make Music. While not a fan of Ivor Tiefenbrunn in general, these Speakers as he so inimitably said: "Can't play da tune!". These Speakers fail to involve me with the music. The Perikles do exactly that.
Fit and finish of the Perikles is first rate. You get as standard a natural wood finish in light cherry, executed to the highest conceivable standards. The drivers used, while not the best in their respective ranges are of a quality that is considerably higher than most what is fitted to sub $ 4,000 Speakers.
Perhaps the best way to illustrate how I feel about these Speakers is this. I have better Speakers at my place sitting face to the wall in the Dining Room. They have been there the last three weeks now, after some repeat swapping and moving of various Boxes. Yet I'm very happy to keep the Perikles in the system, listening through over 10 Hours at a stretch, changing records over and over and just listen. I have up to now put in at least 150 Hours of "serious listening" with these Speakers, covering all sorts of music from Classic and Jazz over Rock, Pop, 1980's New Wave and Electronica to the occasional piece of Hardrock and Metal. Even country music occasionally gets a look in. And for many more hours the Perikles provided background music and worked as sound system for my TV.
Ergo? I Like These Loudspeakers A Lot. So There.
Playing on a nice 2A3 Amp, with a decent Pre and a decent Turntable these Speakers make me musically happy enough to dread moving all these heavy Boxes around. The system is "good enough" to just listen to music and put off rearranging the system until Matthew comes to collect the Perikles. I know only a few other commercially available Speakers that ever did that for me. So far, among them we find a now out of Production Sony "Espirit Series" large size studio-monitor, Wilson Audio's earlier Watt/Puppy Versions, the Beauhorn Virtuoso's, the Epos ES-25 and Naim's DBL's driven fully active by heavily modified Naim Electronics fed from stacks of batteries…. There are other Speakers that I think could do that too, but they tend to be really far out stuff or very large (and expensive) Studio Monitors like the top of the Range PMC Units.
If I had to recommend Amplifiers to drive the Perikles, I think the Sun Audio 2A3 Amp should figure chiefly, also the JC Verdier 2A3 Amp from the "Triode Spirit" Series. I do not know personally any of the Amplifiers Gordon Rankin at Wavelength Audio makes, but I'd wager that any of his Amplifiers would be a very nice match. I also never heard any of the Fi Amp's, but people whose ears I trust IMPLICITLY tell me that the larger 2A3 Amp is absolutely fabulous. I did have the chance to try a kitbuild Cary SE1 from a Friend with KR 2A3 output valves. This also did not bad at all, though it misses some of the authority and speed of the "Legacy" at lower frequencies as well as some of transparency.
You can get the Cary amp, the Perikles Speakers and a set of decent speaker cables and still have change from $ 5,000 to buy a few records or CD's. For that you will have a system that will satisfy musically, while offering very credible performance in all classical "HiFi" Terms. What more could you want?
I Know What. The Perikles Ultimate!
This uses a much higher grade Lowther Driver (the DX3) as well as a better Woofer and Tweeter. Knowing the DX3 quite well from a number of Speakers I believe that this version should alleviate most of my concerns about detail and transparency. It does have a notably higher price though, in the UK it will set you back 3,699 UK Pound, around $ 5,500 at current Exchange rates. And you'd want a REALLY nice Amp like the Borderpatrol 300B SE Amp (around $ 6,000 at current exchange rate). But that would hardly qualify as Bargain, now would it?
You could of course order a Pair Lowther DX-3 from your Local Distributor and just fit them yourself for a lot less than the difference and likely get at least 80% of the upgrade. If I have the time and chance to try this (I have no DX-3's at hand, sadly) I shall report back.
All in all, the Perikles is in many ways a breakthrough for all those who want a Speaker that offers high sensitivity, good Bandwidth and general an excellent and living room friendly package to which to hook up your favorite SE Amp. Unlike most Lowther based Speakers, the Perikles are quite forgiving of less than perfect sources. Unlike many Lowther based speakers the Perikles is free from any major sonic coloration's that will distract from the Music. Unlike most domestically acceptable floorstanding Speakers the Perikles will play loud enough with 3.5 Watt and has some rather nice, full and low Bass with good definition. Unlike most of the common Cone/Dome Speaker that are sold nowadays as "HiFi" Speakers, the Perikles offers low compression of Dynamics and truly low distortion.
If you prefer the dynamic, transparent and cohesive performance of a System like the one described here over the artifice and gimmickry that many conventional "High-End" Systems substitute for musical enjoyment and satisfaction, do try to find a way to audition a pair of these Speakers.
I have very much enjoyed my time with the Perikles and I'm sure you will enjoy them to. I will not be heartbroken to see them go, but if I did not have a pair of very good speakers waiting to again take their rightful place in my living room I guess I'd be talking to my Bank manager right now…
Recommended Amplifier Power: 3 - 100 wpc
Hørning Hybrid Corner Horn Productions
The Geek Files - Technology And Measurements
This is the section that tells you about all the technical details, in case you should care about them or want to know about them.
Technology of the Hørning Perikles
The first Item to talk about perhaps is the Lowther Driver. It is an Item first designed in it's basic guise in the 1930 by an expatriate German living in England, by the name P.G.A.H. Voight and manufactured by Lowther, hence the name. These Drivers are also often called "Lowther/Voight". Mr. Voight BTW held loads of British patents for almost anything you could imagine, including the earliest application of negative feedback, cunningly including the Speaker from the early 1920's!!!!
Anyway, in these 7 or so odd decades Lowther Drivers have changed, but not much. They still feature a fairly skeletal cast frame, exceptionally strong magnets, a very light cone and a 40mm voice coil where part of the voice coil is wound inside the Former and another outside. They have a whizzer cone to radiate higher frequencies and where designed originally as Wideband or full range Drivers to cover around 60Hz - 12kHz when placed in modest horn-loaded enclosures. As in the old Mono Days most listeners sat off axis from the speaker a certain degree of lift in the upper midrange and treble was engineered into the Drivers. This has been retained to this day. With typical stereo placement the Listener sits on or close to the main axis of the Driver, so directly where the increased energy in the midrange is present. The result is a Tonal Balance on the very bright side of neutral, even in most of the rear horn-loaded cabinets these drivers tend to be utilized in.
The next sonic problem Lowther's show according to modern standards are the resonance’s between main cone and the whizzer cone. These lead to a ragged midrange response, even though they make themselves known primarily as notches (lack of output) which are less distracting, subjectively speaking. Tommy Hørning has addressed most of the Lowther's peculiarities very well. First he addresses the problem of the resonance's between whizzer cone and main cone by simply cutting the whizzer cone off. This leaves a driver that can still run full range and will cover up to around 8kHz. The lifted Midrange is still in evidence, no problem, a RLC Equalizer is used to flatten the response. Behind the Driver a Deflex Sheet is located in order to disperse the rear radiation of the cone in the midrange, preventing it from being reflected back through the cone with a short time delay which can cause “smearing” of transients. So, now we have a Driver covering around 60Hz- 8kHz and operating with no conventional Crossover and minimized coloration's.
To offer a true full frequency range reproduction a special cone tweeter made by Hørning is used. A simple crossover consisting of a single capacitor is employed here. The midrange equalizer and tweeter crossovers use highest quality components, including special solid carbon resistors, Jensen copperfoil aircore inductors and copperfoil paper in oil capacitors. Depending upon ones philosophy for parts this is the absolute best or at least very good. The final piece of the puzzle is a massive, cast frame 12” Woofer developed by Beyma for use in large size studio monitors. This unit is used to support the Lowther unit below 200Hz all the way down to the cutoff point of around 40Hz. The Inductor in this crossover is a huge unit with a Iron Dust core and very thick solid copper wire, making for low resistance and losses.
The length of the Horn, a very ingenious contraption which employs unequal length "Tapered Quarterwave" Horns, determines the lower cutoff frequency. Here we have separate sections of different length for the Lowther and the woofer, which combine into one common hornmouth venting out of the bottom of the cabinet. The use of unequal length sections helps evening out the response in the Bass. Common single Tapered Quarterwave Horns are compact and fairly efficient but suffer from uneven bass response due to the resonance’s in the length mode of the horn. By using two unequal length sections these resonances are spread out, offering a much more even bass response.
One of the “sideffects” of having made a high sensitivity Loudspeaker (as the Perikles clearly is with > 96db/2.83V/1m Sensitivity) is that, at least in the case of the Perikles the Speaker is showing significantly LOWER distortion and compression than many common HiFi and even high end speakers. This is clearly audible as a transparency and directness that rivals the better Electrostatic Speakers while offering a much greater ability to portrait macro dynamics. All in all the Perikles shows a number of innovative and less than usual approaches to designing a fairly compact, fairly high sensitivity Speaker with great domestic appeal. The component choice indicates that only minimal compromises where accepted (like the use of the lowest price Lowther Driver, the PM6C), in general it seems the very best part available for the job was considered “”adequate”. Such careful choice tends to pay handsome sonic dividends, as I found when listening to the Perikles. To house all these drivers a heavily braced and reinforced cabinet made from veneered 0.75-inch MDF is used. The front edges are made from radiused solid wood. The real wood veneer work and general fit and finish are of outstanding quality. I have not seen any better in “cost no object” Speakers or in really expensive real wood furniture. The input to the crossover is a single set of massive binding posts, so use rather some good, single wire, speaker cable.
As a general Design the Perikles must be considered a substantial success. It is a Design that not only solves or reduces the common problems plaguing conventional low(ish) sensitivity HiFi Speakers (1, 2) by offering high sensitivity. The Perikles also addresses many of common weaknesses of the high sensitivity systems (3, 4). All this together leaves the Perikles as one of the very few examples of truly competent speaker design anywhere near it’s asking price by offering wide bandwidth, low coloration, low distortion, low compression AND high sensitivity.
Sniping From The Sidelines -
(1) Normal “HiFi” Speakers suffer from compression of dynamics often to the tune of 2 - 3dB at 1 Watt and substantially above 6db at rated power. The heating up of the voice coil, which also alters the Bass behavior of the Speaker (one note and boomy bass when played loud), causes this. Having a high sensitivity reduces compression simply by needing less power for a given sound level, thus causing less heating up of the Voice coil.
(2) Normal "HiFi" Speakers suffer from substantial levels of harmonic distortion (and attendant intermodulation distortion) generated by eddy current losses in the magnet pole pieces. This Distortion follows a cubic function and hence generates primarily odd order harmonics, dominated by third and fifth harmonic. Level of 1% and more Distortion at 1 Watt are not at all uncommon, the better and best HiFi Drivers mange about 0.3% Distortion at 1 Watt (the best Scan Speak, Dynaudio and Skaaning Units to be precise). As the Distortion is related by a cubic function to the current in the voice coil increasing the sensitivity of the speaker can reduce it. If for a given sound level less power and hence less current is needed the distortion will be lower according to the Square of the Power or the Cube of the current. This means that if a Speaker needs only 1 Watt to reproduce 96db and another needs 10 Watt to reproduce 96db the lower sensitivity Speaker will be usually by a factor 10 more distorted for the 96db Level. It is true that methods exist that can reduce distortion, apart from high sensitivity but they are rarely used and often problematic to employ.
(3) High Sensitivity Speakers are usually optimized for sensitivity. This usually generates a frequency response that is less flat than lower sensitivity speakers and often the bandwidth (how low and how high a Speaker will play) is also substantially compromised.
(4) High Sensitivity Speakers that are intended to play low frequencies must usually be very large. There is a direct link between Size, Low Frequency cut-off and available Sensitivity. The lower you go for a given sensitivity or the louder you go for a given low end cut-off, the larger the enclosure. Careful use of room reinforcement and acoustic amplifiers (horns) can be used to circumvent this issue somewhat, though even so, a compact horn system tends to be much larger than the usual “audiophile” Minimonitor.
Measurements For The Hørning Perikles
Unfortunately I did not have the chance yet to set up again my secondary Computer, normally used for audio measurements (I moved house a few month back). So only a rough assessment using a modified and calibrated Radio Shack SPL Meter, a loaned 1/3 Octave Real Time Analyzer (RTA) and B&K measurement Mic as well as several Stereophile Test CD’s where employed.
Measuring Sensitivity with 1V Pink Noise (1 Speaker only) at 1m Distance yielded 87.5dB SPL, this corresponds to 96.5db/2.83V/1m Sensitivity. This is above the manufacturers Specification and so far the only time where I measured the same approximate SPL as claimed by the manufacturer, I usually find anywhere between 3 to 6db lower measured sensitivity using the pink noise method than stated by manufacturers. Using the Stereophile Test-CD1 and the Radio Shack SPL Meter (modified for flat LF response) to test the in room LF Behavior showed a fundamentally flat response with a broadband lift between 160Hz and 60Hz of around 4 to 6db with 40Hz at the same level as 1kHz and 200Hz. Below 40Hz the output dropped dramatically, leaving even 32Hz almost 10db below the level at 40Hz. The kind of room induced lift at LF seen here is common with practically all speakers aligned for flat response under anechoic conditions. It generally creates a warm, big yet “pacey” sound, subjectively quite pleasant and forgiving.
I cannot fault Tommy Hørning for following the same convention as everyone else, but I’d still prefer a fundamentally flat in room response myself.Looking at the in room response of the Speakers (Stereo Pair, taken at the listening position) with the 1/3 Octave RTA showed a well balanced Response. The LF Peaking described above was in evidence. Further notable was a slightly suppressed upper midrange, reminiscent of the classic “BBC Dip”. Such a response shaping is indeed almost to the dot in line with that of the BBC LS3/5 Speakers, leading to a very forgiving perceived balance, even though I again would like a little bit more midrange.
The measured in room response corresponds nicely to the perceived “laid back” balance and the perceived strong Bass. All this criticism counted, under anechoic conditions the Perikles is likely to meet it’s specification and even the in room response on the 1/3 Octave RTA was mostly within a tight +/-5 dB range, quite impressive I might add. The (quite possibly deliberately) shaped frequency response will make the speaker rather forgiving to poor recordings and less than top-notch source equipment or amplifiers. Considering the equipment the Perikles is likely to be partnered with this seems a wise decision. The downside is a slight lack of “edge of the seat” excitement, even though I’d like to note that the Perikles is musically much more communicative and involving than most HiFi or Hi-End Speakers I know.
I was unable to measure distortion or compression at this time, historical data for Lowther drivers would suggest about 0.5% THD @ 96dB/W/m and <1dB compression at 96dB/W/m. This Data applied to the PM2C, not the PM6C used in the Perikles. Subjective Sonics however confirmed a low level of distortion and compression. No specific Tests for power handling where carried out either. This was primarily not done because with even around 3 Watt from a 2A3 Amplifier rather uncomfortable sound levels could be reached clearly and attempting to test this speaker to the notional 100 Watt would have not only endangered my own hearing, but that of the neighbors. Informal tests for Power-requirements where done during listening. Even a pair of #45 Valves in the “Legacy 300B Amp” where able to provide floor shaking bass and subjectively sufficient loudness even for most orchestral works. I would hence personally suggest that even 1.5 Watt are sufficient for the Perikles under most conditions. The choice of Amplifier is more a question of quality than of quantity.
Three cheers for Tommy Hørning for presenting honest Specifications and for not “fiddeling numbers” to make the Speaker look better on paper than it really is in the real world. Three more cheers for a speaker that measures comparatively well, especially considering the relatively small size and high sensitivity.